head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Execution · Competitive PvP
A wrestling game about timing grapples and, versus humans, reading reversals.

Execution · Competitive PvP
Reversal timing and pacing against an opponent baiting your counters.
WCW/nWo Thunder leans Execution (Competitive PvP); WWE 2K15 leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
WCW/nWo Thunder
Grapple and strike timing decide exchanges
WWE 2K15
Reversal timing windows decide most exchanges
WCW/nWo Thunder leans a little harder on reads, though the gap is small.
WCW/nWo Thunder
Human opponents must be anticipated and countered
WWE 2K15
Human opponents bait reversals and vary move timing
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
WCW/nWo Thunder
Reversal windows add some unpredictability
WWE 2K15
Chain-wrestling rock-paper-scissors minigames add randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
WCW/nWo Thunder
Move-set knowledge and stamina management matter
WWE 2K15
Move sets, stamina and match pacing are learnable systems
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.